Figure 4

Phase diagram of Ca as obtained with the present first principle calculation (empty symbols and pink continuous line) and a previous study based on ab initio molecular dynamics simulation³⁶ (dashed black line and light blue triangle) and a high P-T experiment (dashed black lines)⁶. The different symbols used in the graph represent the three different approaches used for the simulations. In particular: the pink squares represent the simulation obtained with 2 valence electrons and 1000 atoms; the brown triangles are obtained using 10 valence electrons and 1000 atoms; the green diamond are obtained using 2 valence electrons and 1960 atoms.